Imperial College London
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ProfessorJohannesLischner

Faculty of Engineering, Department of Materials

Professor of Theory and Simulation of Materials
 
 
 
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Contact

 

+44 (0)20 7594 9949j.lischner

 
 
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Location

 

342Bessemer BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Goodwin:2019:10.1103/PhysRevB.100.235424,
author = {Goodwin, Z and Corsetti, F and Mostofi, A and Lischner, J},
doi = {10.1103/PhysRevB.100.235424},
journal = {Physical Review B: Condensed Matter and Materials Physics},
title = {Attractive electron-electron interactions from internal screening in magic angle twisted bilayer graphene},
url = {http://dx.doi.org/10.1103/PhysRevB.100.235424},
volume = {100},
year = {2019}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Twisted bilayer graphene (tBLG) has recently emerged as a new platform for studying electroncorrelations, the strength of which can be controlled via the twist angle.  Here, we study the effectof internal screening on electron-electron interactions in undoped tBLG. Using the random phaseapproximation,  we find that the dielectric response of tBLG drastically increases near the magicangle  and  is  highly  twist-angle  dependent.   As  a  consequence  of  the  abrupt  change  of  the  Fermivelocity  as  a  function  of  wave  vector,  the  screened  interaction  in  real  space  exhibits  attractiveregions  for  certain  twist  angles  near  the  magic  angle.   Attractive  interactions  can  induce  chargedensity waves and superconductivity and therefore our findings could be relevant to understand themicroscopic origins of the recently observed strong correlation phenomena in undoped tBLG. Theresulting screened Hubbard parameters are strongly reduced and exhibit a non-linear dependence onthe twist angle.  We also carry out calculations with the constrained random phase approximationand parametrize a twist-angle dependent Keldysh model for the resulting effective interaction.
AU  - Goodwin,Z
AU  - Corsetti,F
AU  - Mostofi,A
AU  - Lischner,J
DO  - 10.1103/PhysRevB.100.235424
PY  - 2019///
SN  - 1098-0121
TI  - Attractive electron-electron interactions from internal screening in magic angle twisted bilayer graphene
T2  - Physical Review B: Condensed Matter and Materials Physics
UR  - http://dx.doi.org/10.1103/PhysRevB.100.235424
UR  - https://journals.aps.org/prb/abstract/10.1103/PhysRevB.100.235424
UR  - http://hdl.handle.net/10044/1/75305
VL  - 100
ER  -
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